Cellular Aspects Of Hypertension

In the last two decades, investigations at the cellular level have progressively gained ground in the context of hypertension research. This choice of approach is due to some extent to the build up of know-how that molecular and cellular biology have been producing at a continuous rate. As the contents list of this volume shows, a large mass of work has been directed to gaining some insight into pathogenetic mechanisms. The pathogenesis of primary hypertension has been progressively categorized as a distinct biological problem, not amenable to the theoretical models that proved successful in understanding the nature of secondary forms of hypertension. At the same time, great efforts have been made to simplify this problem by sorting out, if possible, a few crucial mechanisms from the network of contributory factors in the regulation of blood pressure. The idea that what is to be sought is a primary structural and/or functional fault in arterial muscle has met with widespread acceptance. The strength of this argument lies in the fact that peripheral vascular resistance is increased in all forms of hypertension and, in turn, the diameter of resistance vessels is the dominant factor in the computation of total per ipheral resistance. On the basis of this, cardiovascular structural adaptation was proposed as a positive feedback mechanism tending to maintain hypertension, once begun, whatever the initiating factor is.

Hypertension is recognized to be one of the major risk factors for the development of peripheral vascular disease. The last decade has witnessed several major advances in therapy for hypertension, including the development of angiotensin-converting enzyme inhibitors and calcium channel blockers. These compounds have greatly improved the ability to control blood pressure and to reduce the impact of this risk factor on morbidity and mortality. In spite of these advances, cardiovascular disease remains a major health problem in most modern industrialized countries with related deaths exceeding those from all other causes combined. In contrast to these advances in therapy, our understanding of the basic mechanisms responsible for the pathogenesis of hypertension remains incomplete. Recent studies have produced new insights into the nature of the regulation of muscle contraction in both heart and blood vessels as well as the changes in muscle function that occur in hypertension. However, the effects of antihypertensive therapy, both in terms of restoring normal function and in producing reversal of hypertension-associated changes, has not been as thoroughly studied, especially in the vasculature. Studies in the heart suggest that the efficacy of different therapeutic agents in restoring normal function and reversing hypertensive changes vary substantially with the mechanism of action of the therapeutic agent. It has also been recently determined that some therapeutic agents produce adverse effects on plasma lipid profiles, which could lead to the secondary acceleration of the atherosclerotic process, while at the same time normalizing blood pressure.

As the first primer on the effects of exercise on human hypertension, Effects of Exercise on Hypertension: From Cells to Physiological Systems provides the state-of-the-art effects of exercise on the many possible mechanisms underlying essential hypertension in humans. The book contains chapters by distinguished experts on the effects of exercise on physiological systems known to be involved in hypertension development and maintenance as well as less well known aspects of hypertension such as 24-hour ambulatory blood pressure profile and oxidative stress. An emerging area, the effects of resistance exercise training on blood pressure is also covered. A unique aspect of the book is that it covers the effects of exercise mimetics on vascular cell adaptations in order to begin to elucidate some of the cellular mechanisms that may underlie blood pressure reductions with exercise training. Lastly, the book will end with a chapter on the interactive effects of genes and exercise on blood pressure. Chapters are grouped by physiological system or mechanism. The text begins with two overview chapters; one on the general effects of aerobic exercise training and the second on the general effects of resistance exercise training on blood pressure. Each chapter begins with a bulleted list of key points. Effects of Exercise on Hypertension: From Cells to Physiological Systems will be of great value to professional individuals in cardiovascular medicine, the cardiovascular sciences, allied health care professionals, and medical and graduate students in the cardiovascular sciences and medicine.

Diabetes and hypertension have evolved as two of the modern day epidemics affecting millions of people around the world. These two common co-morbidities lead to substantial increase in cardiovascular disease, the major cause of morbidity and mortality of adults around the world. In Diabetes and Hypertension: Evaluation and Management, a panel of renowned experts address a range of critical topics -- from basic concepts in evaluation and management of diabetes and hypertension, such as dietary interventions, to evaluation and management of secondary hypertension in clinical practice. Other chapters focus on high cardiovascular risk populations such as those with coronary heart disease, chronic kidney disease and minority patients. In addition, evolving concepts and new developments in the field are presented in other chapters, such as prevention of type 2 diabetes and the epidemic of sleep apnea and its implication for diabetes and hypertension evaluation and management. An important title covering two of the most troubling disorders of our time, Diabetes and Hypertension: Evaluation and Management will provide the busy practitioner with cutting edge knowledge in the field as well as practical information that can translate into better care provided to the high-risk population of diabetics and hypertensive patients.

This presentation describes various aspects of the regulation of tissue oxygenation, including the roles of the circulatory system, respiratory system, and blood, the carrier of oxygen within these components of the cardiorespiratory system. The respiratory system takes oxygen from the atmosphere and transports it by diffusion from the air in the alveoli to the blood flowing through the pulmonary capillaries. The cardiovascular system then moves the oxygenated blood from the heart to the microcirculation of the various organs by convection, where oxygen is released from hemoglobin in the red blood cells and moves to the parenchymal cells of each tissue by diffusion. Oxygen that has diffused into cells is then utilized in the mitochondria to produce adenosine triphosphate (ATP), the energy currency of all cells. The mitochondria are able to produce ATP until the oxygen tension or PO2 on the cell surface falls to a critical level of about 4–5 mm Hg. Thus, in order to meet the energetic needs of cells, it is important to maintain a continuous supply of oxygen to the mitochondria at or above the critical PO2 . In order to accomplish this desired outcome, the cardiorespiratory system, including the blood, must be capable of regulation to ensure survival of all tissues under a wide range of circumstances. The purpose of this presentation is to provide basic information about the operation and regulation of the cardiovascular and respiratory systems, as well as the properties of the blood and parenchymal cells, so that a fundamental understanding of the regulation of tissue oxygenation is achieved.

Cellular and Molecular Pathobiology of Cardiovascular Disease focuses on the pathophysiology of common cardiovascular disease in the context of its underlying mechanisms and molecular biology. This book has been developed from the editors' experiences teaching an advanced cardiovascular pathology course for PhD trainees in the biomedical sciences, and trainees in cardiology, pathology, public health, and veterinary medicine. No other single text-reference combines clinical cardiology and cardiovascular pathology with enough molecular content for graduate students in both biomedical research and clinical departments. The text is complemented and supported by a rich variety of photomicrographs, diagrams of molecular relationships, and tables. It is uniquely useful to a wide audience of graduate students and post-doctoral fellows in areas from pathology to physiology, genetics, pharmacology, and more, as well as medical residents in pathology, laboratory medicine, internal medicine, cardiovascular surgery, and cardiology. Explains how to identify cardiovascular pathologies and compare with normal physiology to aid research Gives concise explanations of key issues and background reading suggestions Covers molecular bases of diseases for better understanding of molecular events that precede or accompany the development of pathology